The knurl might be what shows after the original limiter caps have been pulled off. Most new saws are leaned way out at the factory to meet emission limits, and the caps get removed to permit proper adjustment after break-in. If no slot is there on the needle valves, use a length of fairly firm plastic tubing that fits snugly against the tapered knurl. Unscrew the needles and flatten and slot the ends with a thin cut-off disk on a dremel or with a thin flat needle file.

“The knurl might be what shows after the original limiter caps have been pulled off. Most new saws are leaned way out at the factory to meet emission limits, and the caps get removed to permit proper adjustment after break-in. If no slot is there on the needle valves, use a length of fairly firm plastic tubing that fits snugly against the tapered knurl. Unscrew the needles and flatten and slot the ends with a thin cut-off disk on a dremel or with a thin flat needle file.

the poulans he's talking about never came with limiter caps. the special tool is their way of preventing people from adjusting the jets.
you won't turn the jets with a piece of tubing, the springs are too strong. you need the tool or a slot to turn them, hence the info given earlier.

“The knurl might be what shows after the original limiter caps have been pulled off. Most new saws are leaned way out at the factory to meet emission limits, and the caps get removed to permit proper adjustment after break-in. If no slot is there on the needle valves, use a length of fairly firm plastic tubing that fits snugly against the tapered knurl. Unscrew the needles and flatten and slot the ends with a thin cut-off disk on a dremel or with a thin flat needle file.

You can do as you say to put a slot on the end of the needles, but it's a PITA to get a screwdriver on them when the thing is running, too much room in there to guide the screwdriver in. The tool makes it slick and easy.

I just removed the limiters from a 2150 today, and the Poulan tool fits perfectly evan though they have a screwdriver slot in them, it's much easier this way.

“the poulans he's talking about never came with limiter caps. the special tool is their way of preventing people from adjusting the jets.
you won't turn the jets with a piece of tubing, the springs are too strong. you need the tool or a slot to turn them, hence the info given earlier.

If you dont want to go by the service place or wait a week on the tool, you can try a wiring butt connector. Slide the wiring connector down over the splines and see if it will grab tight enough to turn. You may have to take the recoil side cover off to get in there. If that wont work you can try a section of a brass tubing that you tap on over the splined jets. You can buy the brass tubing at any craft place or hardware store. 1/8 inch ID is just about right.

Consider removing the jets one at a time and slotting them with a dremel or a hacksaw for future use.

I wish all saws came with this type of adjust they are so easy when you have the right tool.
Dealers will not sell the tool as they are subject to a $3000 fine if they do, but you can get them off e bay and thy are worth having.